Vehicle-Mounted Control Device

A vehicle-mounted control device capable of detecting disconnection failure of a GND line of an electronic control device without adding a circuit and identifying between disconnection failure of the GND line of the electronic control device and disconnection failure of an electric load is realized. The vehicle-mounted control device is supplied with a drive voltage from a voltage source via the GND line and drives a plurality of electric loads. Further, the vehicle-mounted control device includes a voltage monitoring unit that measures a voltage of the voltage source to be supplied to the electric load; a current monitoring unit that measures a current flowing through the electric load; a driving unit that adjusts an energization amount of the electric load; a current cutoff determination unit that determines whether the driving unit cuts off the current flowing through the electric load; and a disconnection identification diagnosis unit that identifies between a disconnection failure of the electric load and a disconnection failure of the GND line